Electrical Contact Technique For Electrochromic Windows
A window assembly comprises a first conductive material layer, an electrochromic stack, a second conductive material layer and a seal. The first conductive material layer is formed on a substrate and comprises at least two zones electrically isolated from each other. The electrochromic stack is formed on a first selected zone of the first conductive material layer to overlap an edge of a second selected zone of the first conductive material layer. The second conductive material layer is formed on the electrochromic stack to overlap an edge of the second selected zone. A first bus bar is formed on the second selected zone to be within a sealed volume of the window assembly. A second bus bar is formed on the first selected zone to be outside the seal volume of the window assembly. The seal defines the sealed volume of the window assembly and seals the window assembly.
The subject matter disclosed herein relates to dynamic windows, such as smart windows. More particularly, the subject matter disclosed herein relates to a technique for making electrical contact to a dynamic window, such as a dynamic Insulated Glass Unit (IGU) window assembly.
For a conventional dynamic IGU, the transparent conducting layer of an electrochromic pane is semi-hermetically sealed within the IGU and electrical contact must be made between the transparent conducting layer and the exterior of the sealed IGU. Conventional techniques for making the electrical contact involve using a fired, silk screened or soldered bus bar.
The breaching of seal 102 by bus bar 101 reduces the reliability of seal 102.
The subject matter disclosed herein is illustrated by way of example and not by limitation in the accompanying figures in which like reference numerals indicate similar elements and in which:
As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not to be construed as necessarily preferred or advantageous over other embodiments.
The subject matter disclosed eliminates a bus bar from running underneath the seal which, in turn, eliminates one of the highest risk reliability failure modes in a finished IGU product by utilizing a conducting substrate as a contact path for control signals in place of a conventional bus bar. Another benefit of the subject matter disclosed herein is that bus bars can take up shapes on more of the perimeter of the coating inside the volume which enhances performance of the electrical operation of the electrochromic (EC) stack.
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While the exemplary embodiments disclosed herein are formed with two electrically isolated zones, it should be understood that more than two electrically isolated zones could be formed for a multi-zone dynamic IGU. Additionally, while the exemplary embodiments disclosed herein are formed so that the two conductive material layers cover substantially the same area as the electrochromic stack, it should be understood that at least one conductive material layer could be formed to cover an area that is substantially different from the area of the electrochromic stack. Further, an alternative exemplary embodiment provides that the electrochromic stack is formed so that it does not overlap the isolation line. For this alternative exemplary embodiment, an additional masking step is required to keep the electrochromic stack from overlapping the isolation line, while the second (or top) transparent conductive layer overlaps the isolation line. Yet another exemplary embodiment provides that the electrochromic stack overlaps one or more selected portions of the isolation line.
Although the foregoing disclosed subject matter has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced that are within the scope of the appended claims. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the subject matter disclosed herein is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.
Claims
1. A window assembly, comprising:
- a first conductive material layer formed on a substrate, the first conductive material layer comprising at least two zones that are each electrically isolated from each other;
- an electrochromic stack formed on a first selected zone of the first conductive material layer to overlap at least an edge of a second selected zone of the first conductive material layer;
- a second conductive material layer formed on at least a portion of the electrochromic stack to overlap at least an edge of the second selected zone of the first conductive material layer;
- a first bus bar formed on the second selected zone of the conductive material layer, the first bus bar comprising a position that will be within a sealed volume of the window assembly; and
- a second bus bar formed on the first selected zone, the second bus bar comprising a position that will be outside the seal volume of the window assembly.
2. The window assembly according to claim 1, further comprising a seal defining the sealed volume of the window assembly.
3. The window assembly according to claim 1, wherein the electrochromic stack comprises:
- a counter electrode (CE) layer formed on the first conductive material layer in the first selected zone of the first conductive material layer;
- an ion conductor (IC) layer formed on the counter electrode (CE) layer; and
- an electrochromic (EC) layer formed on the ion conductor (IC) layer.
4. The window assembly according to claim 3, wherein the second conductive material layer is formed on the electrochromic (EC) layer of the electrochromic stack.
5. The window assembly according to claim 4, further comprising a seal defining the sealed volume of the window assembly.
6. The window assembly according to claim 1, wherein the electrochromic stack comprises:
- an electrochromic (EC) layer formed on the first conductive material layer in the first selected zone of the first conductive material layer;
- an ion conductor (IC) layer formed on the electrochromic (EC) layer; and
- a counter electrode (CE) layer formed on the ion conductor (IC) layer.
7. The window assembly according to claim 6, wherein the second conductive material layer is formed on the electrochromic (EC) layer of the electrochromic stack.
8. The window assembly according to claim 7, further comprising a seal defining the sealed volume of the window assembly.
9. A method, comprising:
- forming a first conductive material layer formed on a substrate, the first conductive material layer comprising at least two zones that are each electrically isolated from each other;
- forming an electrochromic stack on a first selected zone of the first conductive material layer to overlap at least an edge of a second selected zone of the first conductive material layer;
- forming a second conductive material layer on at least a portion of the electrochromic stack to overlap at least an edge of the second selected zone of the first conductive material layer;
- forming a first bus bar on the second selected zone of the conductive material layer, the first bus bar comprising a position that will be within a sealed volume of the window assembly; and
- forming a second bus bar on the first selected zone, the second bus bar comprising a position that will be outside the seal volume of the window assembly.
10. The method according to claim 9, further comprising forming a seal defining the sealed volume of the window assembly.
11. The method according to claim 9, wherein forming the electrochromic stack comprises:
- forming a counter electrode (CE) layer on the first conductive material layer in the first selected zone of the first conductive material layer;
- forming an ion conductor (IC) layer on the counter electrode (CE) layer; and
- forming an electrochromic (EC) layer on the ion conductor (IC) layer.
12. The method according to claim 11, wherein forming the second conductive material layer comprises forming the second conductive material layer on the electrochromic (EC) layer of the electrochromic stack.
13. The method according to claim 12, further comprising forming a seal defining the sealed volume of the window assembly.
14. The method according to claim 9, wherein forming the electrochromic stack comprises:
- forming an electrochromic (EC) layer on the first conductive material layer in the first selected zone of the first conductive material layer;
- forming an ion conductor (IC) layer on the electrochromic (EC) layer; and
- forming a counter electrode (CE) layer on the ion conductor (IC) layer.
15. The method according to claim 14, wherein forming the second conductive material layer comprises forming the second conductive material layer on the electrochromic (EC) layer of the electrochromic stack.
16. The window assembly according to claim 15, further comprising a seal defining the sealed volume of the window assembly.
17. A window assembly, comprising:
- a first conductive material layer formed on a substrate, the first conductive material layer comprising at least two zones that are each electrically isolated from each other;
- an electrochromic stack formed on at least a portion of a first selected zone of the first conductive material layer;
- a second conductive material layer formed on at least a portion of the electrochromic stack to overlap at least an edge of a second selected zone of the first conductive material layer;
- a first bus bar formed on the second selected zone of the conductive material layer, the first bus bar comprising a position that will be within a sealed volume of the window assembly; and
- a second bus bar formed on the first selected zone, the second bus bar comprising a position that will be outside the seal volume of the window assembly.
18. The window assembly according to claim 17, further comprising a seal defining the sealed volume of the window assembly.
19. The window assembly according to claim 17, wherein the electrochromic stack comprises:
- a counter electrode (CE) layer formed on the first conductive material layer in the first selected zone of the first conductive material layer;
- an ion conductor (IC) layer formed on the counter electrode (CE) layer; and
- an electrochromic (EC) layer formed on the ion conductor (IC) layer.
20. The window assembly according to claim 19, wherein the second conductive material layer is formed on the electrochromic (EC) layer of the electrochromic stack.
21. The window assembly according to claim 20, further comprising a seal defining the sealed volume of the window assembly.
22. The window assembly according to claim 17, wherein the electrochromic stack comprises:
- an electrochromic (EC) layer formed on the first conductive material layer in the first selected zone of the first conductive material layer;
- an ion conductor (IC) layer formed on the electrochromic (EC) layer; and
- an counter electrode (CE) layer formed on the ion conductor (IC) layer.
23. The window assembly according to claim 22, wherein the second conductive material layer is formed on the electrochromic (EC) layer of the electrochromic stack.
24. The window assembly according to claim 23, further comprising a seal defining the sealed volume of the window assembly.
Type: Application
Filed: Sep 17, 2008
Publication Date: Mar 18, 2010
Patent Grant number: 7719751
Inventors: Peter Egerton (Windsor, CA), Drew Gaskell (Santa Rosa, CA)
Application Number: 12/212,482
International Classification: G02F 1/153 (20060101);